DE3014451C2 - Apparatus and method for automatically fusing optical fibers - Google Patents

Description

Withdrawing the reference element;
Unlocking the locking means to allow the holder to move as far as it will go against the micrometer drive head;
Actuation of an electric drive motor to adjust the micrometer drive head backwards to a position in which the holder comes to rest against a first stop;

Withdrawing the first stop;
Starting a discharge heating source for a predetermined period of time after retraction of the first stopper;
further advancing the micrometer drive head rearward to allow the bracket to further move into position until it abuts a second stop;

Putting the discharge heating source out of operation; and

Resetting of the holder, the reference element, the first stop and the Mikrorneterantriebsköpfes in the starting positions.

4. The method according to claim 3, characterized by the following steps:

Withdrawing the reference element;
Unlocking the locking means to the

Bracket to allow movement until it stops on the micrometer drive head;
Energizing an electric motor to move the micrometer drive head rearward to bring the bracket to a first predetermined position;
Commissioning of a Eniladungsheizquelle over a predetermined period of time after the mounting its first predetermined position · ⁰ has taken;

further moving back the meter drive head to allow the holder to move to a position in which it is intercepted against a stop in a second, predetermined position;
Putting the discharge heating source out of operation, and

Return the holder, the reference element and the micrometer drive head in the starting positions.

5. A method for fusion bonding optical fibers according to one of claims 3 or 4, characterized by the following steps:

Withdrawing the reference element;
Actuating a stepping motor to retract a micrometer drive head to move the bracket to a first predetermined position;

Starting a discharge heating source for a predetermined period of time after the holder has assumed its first predetermined position;

moving the micrometer drive head back further by operating the stepper motor, to move the bracket forward to a second predetermined position; Shutting down the discharge heating source: and

Return the holder, the reference element and the micrometer drive head in their starting positions.

The invention relates to a device and a method for the automatic fusion connection of

w optical fibers in the arc of such a device known from Japanese utility model 54 14 550 has support brackets for supporting the optical fibers, brackets for holding the optical fibers, brackets for holding the optical fibers on both sides of a reference element, with at least one of the brackets in fiber -Axial direction is movable by spring force, a heat source and a drive source.
This known device has the disadvantage that the positions of the movable holder assigned to the respective work steps cannot be clearly defined, so that the fusion connection of the two optical fiber ends cannot be carried out with the desired accuracy.

The invention is therefore based on the object of providing a device as described in the preamble of the above Claim 1 specified generic form so that the fiber ends in the brackets clearly positio-

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can be used to keep the reject rate as low as possible as possible to keep.

This object is achieved by the invention specified in the preceding claim 1 with regard to the creating device solved. With regard to a method improving the disadvantageous prior art for automatically fusing optical fibers in the arc, that of the invention becomes The underlying object is achieved by the invention specified in claim 3.

The technical progress that can be achieved with the aid of the invention is, as far as the device is considered, primarily in the fact that now, with the help of the precisely guided brackets, exact fusion connections can be made between the light guide ends.

In the process according to the invention, technical progress is primarily that the Fusion connection can be carried out practically automatically.

According to a preferred embodiment of the device according to the invention it is provided that the Reference element and one of the stops in the axial direction - based on the optical fibers - are movable.

In the method according to the invention, the optical fibers to be connected to one another by a fusible link are supported by support devices and held in place by holders, at least one of which is movable and is initially held by locking means so that the ends of the optical fibers rest on both sides of a reference element. Thereafter, the reference element is withdrawn, at the same time the locking means are released in order to allow the movable holder to move up to the micrometer drive head. The electric motor is then started in order to retract the micrometer drive head in order in this way to bring the movable holder into a position in which it rests against a first stop. This first stop is then withdrawn, at the same time a charge heating source is activated for a predetermined period of time when the first stop is withdrawn. Then the micrometer drive head is withdrawn further to allow the movable bracket to move forward further up to c ^; To allow ne position in which it rests against a second stop. Here the discharge heating source is put out of operation. Then the movable bracket, the reference element, the ersi? Stop and the micrometer drive head each moved back to its starting position. In a variant of this method, the first stop is omitted and this position for the holder is determined by the micrometer drive head itself, which is held in this position in a manner that is not designated. In a further embodiment variant of this method according to the invention, all of the aforementioned stops are omitted and the electric drive motor is replaced by a stepping motor. The different positions of the micrometer drive head, which replace the positions of the stops, are defined by different angles of rotation of the stepping motor.

The invention is illustrated in the following by means of Aüsfühfungsbeispielen and with reference to Drawing described in more detail, In this shows

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b5 F i g. 1 is a schematic representation of an apparatus for fusible bonding of optical fibers in need of improvement;

F i g. 2 is a schematic representation of a preferred Embodiment of a device according to the invention for fusion-bonding optical fibers.

In Fig. 1, optical fibers 1, Γ are supported at their ends freed from the sheath by support devices 2, 2 '. Holders 3, 3 'are provided to hold the fibers in the area of their sheathing. A reference element 4 is inserted between the fiber ends and determines the mutual distance between the ends of the fibers. A compression spring 5 loads the holder 3 ′, which is movable in the axial direction of the fibers, in the direction of the reference element 4. An electric drive motor 8 is in drive connection with a micrometer drive head 6 via gears 7, T. The micrometer drive head 6 engages in the movement path of the holder 3 '.

For fusion bonding, the fibers, from the ignition sections of which the covering has been removed, are first placed on the support devices Γ, V and then displaced in the axial direction, their ends resting against the reference element 4. The fibers, together with their sheathing, are then fixed by the holders 3, 3 '. The electrodes used to create the arc discharge to fuse the optical fibers are shown in FIG. 1 is omitted for the sake of clarity. Usually, these electrodes are mounted stationary perpendicular to the plane of the drawing, the axes of the electrodes lying in the line 19, ie on the left-hand surface of the reference element 4 in FIG. 1. The axes of the electrodes are thus perpendicular to the fibers 1, 1 '.

After pressing a start button (not shown), the reference element 4 is automatically pulled downwards and at the same time the drive motor 8 is started. The rotary movement of the drive motor 8 is transmitted through the gears 7, T to the micrometre drive head 6, so that it also rotates. The direction of rotation of the motor is selected so that the end of the micrometer drive head 6 facing the holder 3 'is withdrawn. Under the force of the spring 5, the holder 3 is therefore moved forward on guide rails (not shown).

At the same time as the motor starts rotating, a timer is set in motion that causes the electrodes to discharge. The discharge takes place over a period of time T ₁ , which can be determined from the following equation:

/ - VT, = α.

where / the width of the reference element, V the Gerchv.mdigkeit of the end of the optical fiber pushed forward by the rotary movement of the drive motor, and α = 10 to 50 μm. After the discharge starts, the optical fiber is continuously advanced. Your movement will stop after a period of time Γ? interrupted after the start of discharge. The time period T2 can be determined using the following equation;

VT ₂ = cc - ε,

where e <= -5 to -50 μm.

The discharge is interrupted after a period of time T3 after its start, at which point the fused connection of the fibers has already been established.

After the discharge is interrupted, the interconnected fibers are removed from the device. A reset button (not shown) is then pressed, whereupon the drive motor is rotated in its opposite direction and is put out of operation after a period of time Ta. The time span % can be determined using the following equation:

VTa = / - e

As can be seen from the foregoing description, according to this technique, which needs improvement, is speed of the motor rotation kept constant in order to set the aforementioned time periods exactly, with which the positions of the fibers are determined. Nevertheless, this technique has disadvantages, because in practice both the speed of the motor and the signals at the output of the timer can vary. However, such deviations from the setpoint values lead to inexact positioning the fiber ends and thus poor fusion connections of the optical fibers.

A first, not shown embodiment of an automatic device for fusion bonding optical fibers according to the invention instead of the motor described in FIG Stepping motor (pulse motor) that performs the required rotary movements with much higher accuracy or can generate angles of rotation for the micrometer drive head. As a result, there is no timer or comparable link more necessary. The positioning of the fibers can be done with extraordinary accuracy, d. H. within a tolerance range of ± 1 μίτι, are executed.

A second preferred embodiment of the automatic fusion bonding apparatus optical fibers according to the invention is shown in FIG. 2, with the same components for the same Reference numerals are used as in Fig. 1. In this embodiment of the device additional stops 9, 10 and 11 are arranged. The bracket 3 '. which is movable and the one fiber is coupled to the reference member 4 by a link mechanism (not shown).

In the in F ι g. 2, in which the reference element 4 is pushed up and between the fiber ends. the holder 3 'is held on the stop 11 by a locking mechanism. As soon as the reference element 4 is withdrawn, the locking mechanism is released so that the holder 3 can move under the force of the spring 5 up to the stop on the micrometer drive head. If the micrometer drive head 6 is then moved back as a result of a rotation of the motor 8, the holder 3 'moves until it rests against the stop 9. The holder is fixed by the stop 9, while the micrometer drive head 6 moves back further until it finally comes to a distance of 5 or 6 μπι is located behind the stop 9. At this point in time, at which the distance α is present between the ends of the fibers 1, 1 ', the discharge heating begins.

Subsequently, the stop 9 is perpendicular to the

■ "'Drawing plane dragged to a position where the Movement of the bracket 3 is not sealed. the Bracket 3 'then moves forward by 5 or 6 μm, until it applies the spring 5 against the end of the micrometer drive head 6 standing by.

While the stop 9 is being moved away, the micrometer drive head 6 is also moved. Accordingly, the holder V follows the micrometer probe head 6 until it comes to rest against the stop 10 and is stopped. In this case the distance is

π between the ends of the fibers has been reduced to.

At this point, the drive motor 8 is either activated by a timer or by a limit switch (not shown) stopped. It should be emphasized that at the point in time at which the drive motor stopped

2 " , the rviikrorneieraniriebskopt b has already been withdrawn so far that the holder 3 'comes to rest against the stop 10.

After that, the fused fibers are made out

removed from the device and rotated the drive motor in the opposite direction by pressing a reset button (not shown) is pressed. As a result, the micrometer drive head 6 is moved forward, the Reference element 4 pushed up and the bracket 3 'by the hinge mechanism so far

JO moved backwards until it rests against stop 11 and is locked to it.

As is clear from the previous description

results, the micrometer drive head has the task of Keeping the speed of the moving fiber constant. It does not determine the respective position of the Fiber.

When the position where the bracket 3 'on

Micrometer drive head 6 comes to rest as soon as the lock is released, at the point of Stop 9 is located, this stop 9 can be omitted. That way the build up of the device can be simplified, although in this case the accuracy of the positioning of the fibers is slightly affected. Nevertheless this «

■ * 5 modification easily usable results even if slight fluctuations in the discharge time can be accepted.

This modification leads to an overall reduction in the overall dimensions of the device.

As also emerged from the above description. is the determination according to the invention the positions of the optical fibers during fusion bonding can be carried out with particular accuracy. This results in a particularly stable fusion bond of the optical fibers with extremely little scrap.

1 sheet of drawings

Claims (3)

Patent claims: 1. Device for automatic fusion connection of optical fibers in the arc with support brackets to support the optical fibers, Holders for holding the optical fibers on both sides of a reference element, so that at least one of the holders is movable in the fiber axial direction by spring force, a heat source and a drive source characterized by a micrometer drive head (6) with which the holder (3 ') under the action of a spring (5) by means of an electric drive motor (8) is movable forwards or backwards at a predetermined speed and by a A plurality of stops (9,10,11) for stopping the holder (3 ') in predetermined positions, wherein the reference element (4), the stops (9, 10, 11), the micrometer drive head (6) and the heat source are movable in a predetermined sequence in such a way that the end of the in the holder (3 ') held optical fiber (Γ) is gradually displaceable into positions which are determined by the Positions of the stops (9,10,11) are determined. 2. Device according to claim 1, characterized in that the reference element (4) and one of the stops (9,10,11) in axial; Direction - based on the optical fibers (1, V) - are movable. 3. A method for fusion-bonding optical fibers using the apparatus according to Claims 1 and 2, wherein optical fibers are held by support devices and brackets and one of the Hal'srungt is movable and can be fixed by locking means such that the Ends of the fibers on both sides of the reference element present, characterized by the following steps: